Installation and wiring of DEIF Multi line 2

DEIF Multi line 2 Generator Controller Installation and Debugging Complete Guide

In the fields of diesel generator sets, marine power systems, and emergency power sources, the DEIF Multi line 2 series controllers (including GPU generator protection units, GPC generator parallel controllers, and PPU power station parallel units) are renowned for their high integration, flexible scalability, and reliable performance. For on-site engineers, correct mechanical installation, electrical wiring, and parameter configuration are key to ensuring safe grid connection and stable operation of the unit. This article is based on the Multi line 2 installation manual (version 2.40.0 and above), which systematically outlines the technical points of the entire process from unboxing to power on debugging, and provides practical suggestions combined with common engineering pain points to help engineers quickly complete project delivery.

Overview of Product Positioning and Selection

Multi line 2 is a microprocessor control platform designed by DEIF specifically for medium to large generator sets, integrating three-phase true RMS measurement, LCD human-machine interface, multiple protection functions, and rich expandable I/O. The three major models correspond to their respective core applications:

GPU (Generator Protection Unit): Focusing on single machine protection, it has ANSI protection such as reverse power (32) and overcurrent (51 two-stage), built-in event recording (150) and GSM SMS alarm, and can be independently used as the main protection of the power station.

GPC (Generator Parallel Controller): Based on GPU, it adds synchronization, active/reactive power allocation, fixed frequency/power, and droop control, supporting parallel connection with multiple units or the power grid.

PPU (Power Plant Parallel Unit): Similar in function to GPC, but focusing on power management of multiple power stations, it can achieve load dependent start stop control.

In terms of hardware, the three share the same chassis structure and card slot system, and optional modules (such as voltage/reactive power regulation, analog output, engine communication) are interchangeable, greatly simplifying spare parts management.

Mechanical installation: panel opening and fixing method

The controller body adopts IP20 protection level, and the display unit can reach IP54 (front panel) through optional sealing gasket. There are two standard installation methods:

DIN rail installation: suitable for non vibration environments, fast and convenient.

Base screw fixation (recommended): There are 6 screw holes on the back of the chassis, requiring 6 M4 screws to be tightened. In situations where vibration is required, such as ships, base screws must be used for fixation to withstand 10g impact and 2g vibration.

The panel opening size strictly follows page 76 of the manual: display unit opening H × W=10mm × 30mm, display module shape 115mm × 220mm. It is recommended to use laser cutting to ensure accuracy. When installing, pay attention to the display cable (option J1/J2) length not exceeding 6 meters, and use Belden 9540 or equivalent shielding wire to avoid signal attenuation.

Hardware board slot structure and I/O allocation

Multi line 2 adopts standardized 8-slot backplates (Slot # 1~# 8) internally, with fixed functions for each slot, making it easy for engineering customization and on-site replacement. Understanding slot allocation is the first step in proper wiring:

Slot Function (GPC/PU) Function (GPU)

#1 power board (including status relay, 4 programmable outputs, open collector electrode pulse output, 5 binary inputs) is the same as GPC, but only has 4 outputs (no synchronous output)

#2 communication options (CANopen/Modbus/Profibus) are the same as GPC

#3 Load Distribution Board (± 5V active/reactive bus, ± 10V set value input, additional binary input and relays 5-8) Synchronous Control Board (G2 option only, including manual speed/voltage regulation input and relays 5-7)

#4. The output of the speed/voltage regulating relay (or optional analog/PWM output) is the same as GPC (but the voltage regulating output is only valid when the D1 option is selected)

#5 AC measurements (generator voltage, current, bus voltage) are the same as GPC (no bus voltage)

#6 analog transmission output (F1) or PWM droop (EF3) with GPC (F1 or F2)

#7 engine control cards (M1 or M2, including PT100, 4-20mA, speed, start/stop relay) are the same as GPC

#8 I/O extensions (7 binary inputs M13, or 4 relays M14, or 4 analog inputs M15, or engine communication H4/H5/H6) are the same as GPC, with additional load dependent start stop relay options

Engineering Tip: The terminal numbers for each slot are consecutive (e.g. # 1 is 1-28, # 2 is 29-36, etc.). Before wiring, be sure to refer to the terminal function table in the manual to avoid misconnection. Especially the current input terminal (73-78) of slot # 5 needs to be strictly connected according to s1/s2 polarity, otherwise the phase difference will cause power calculation errors.

Communication wiring: Voltage, current, and frequency measurement

1. Voltage input (terminals 79~89)

Connect the generator voltage (UL1, UL2, UL3) to 79, 81, and 83, and connect the neutral point N to 84; Bus voltage (if GPC/PU) is connected to 85, 87, 89, and neutral N is connected to 88.

The maximum phase to phase voltage is 690V AC, which can adapt to the range of 100~690V (UL certification limits 110~480V).

It is recommended to use a 2A slow melting fuse to protect the measurement circuit. If the "black start synchronization" function (menu 2040) is enabled, it is recommended to use an automatic fuse with auxiliary contacts on the busbar side. When the fuse is damaged, it can be locked and closed through binary input to prevent accidental parallel connection.

2. Current input (terminals 73~78)

Supports 1A or 5A CT secondary side, with two lines per phase (s1, s2). CT grounding can be carried out at either end of s1 or s2, but it must be ensured that the entire circuit is grounded at one point.

The current input can withstand 4 × In continuously, 20 × In continuously for 10 seconds, and 80 × In continuously for 1 second, meeting the transient requirements of the fault.

Attention: If single-phase or phase separated wiring is used on site (such as single-phase generators), the measurement system configuration needs to be modified in the software menu, otherwise three-phase imbalance will cause false alarms.

3. Frequency measurement range

The controller automatically tracks 30~70Hz with an accuracy of Class 1.0 (negative sequence current Class 2.0). Ensure that the voltage signal is not lower than 30V in order to reliably measure the frequency.

DC power supply, binary input, and relay output

1. Power supply (terminals 1-2)

Supports 12/24V DC (8-36V continuous, minimum 6V can last for 1 second), with a maximum power consumption of 8W.

It is recommended to use the DEIF DCP-2 power module and connect it in series with a 2A slow melting fuse.

Built in power monitoring relay (terminals 3-4, normally closed), when the processor or power supply is abnormal, the contacts will disconnect and can be connected to an external alarm circuit.

2. Binary input (terminals 23-28, 43~55114~118, etc.)

All are bidirectional optocouplers, with an ON voltage of 8-36V DC and an OFF voltage below 2V, and a typical impedance of 4.7k Ω.

Can be configured for remote alarm suppression, alarm confirmation, speed/voltage regulation, mode selection, circuit breaker status (on/off), etc. Important: All dry contacts require an external power supply (24V wet connection provided by the controller). Do not connect external voltage, otherwise it may damage the optocoupler.

3. Relay output

The contact is rated at 250V AC/8A (resistive) and can be directly connected to circuit breaker closing coils, speed regulator frequency up and down signals, AVR voltage up and down signals, etc.

For inductive loads (such as contactors), RC absorption circuits or varistors must be connected in parallel for noise suppression, otherwise it may cause controller reset. Typical circuits can be found on page 54 of the manual.

4. Open electrode pulse output (terminals 20-22)

Used for kWh and kVArh pulse counting, with a maximum load of 10mA (requiring an external pull-up resistor to 8~36V DC), and cannot directly drive relays.

Analog input/output and set value wiring

1. Input of active/reactive power setting values (terminals 40-42)

0~10V or ± 10V analog quantity (passive type, requiring external power supply), can be provided by PLC output or potentiometer voltage division. Impedance 100k Ω, pay attention to shielding and grounding.

2. Load distribution line (terminals 37-39)

Used for transmitting active (terminal 37) and reactive (terminal 39) load signals when multiple machines are connected in parallel, with a signal range of -5~0~+5V and an impedance of 23.5k Ω. Shielded twisted pair cables must be used with a single end grounded to avoid common mode interference and distribution loss of control.

3. 4-20mA transmission output (options F1/F2)

Can be configured as active power, reactive power, current, voltage, etc. of the generator, actively output (internal power supply), with a maximum load of 500 Ω. The accuracy meets Class 1.0.

4. Engine sensor input (options M1/M2)

M1 provides 4 channels of 4-20mA (terminals 98-105), 2 channels of Pt100 (106-111), and 1 channel of magneto electric speed (112-113). Pt100 is connected in a three wire system and complies with EN 60751.

M2 provides 3 VDO resistance sensors (such as oil pressure, water temperature, and liquid level), sharing a common terminal and providing an internal pull-up resistor.

Communication Network Configuration and Engineering Key Points

Multi line 2 supports three mainstream fieldbus options, all located in slot # 2:

1. CANopen（H1）

Using shielded twisted pair cables, terminals 29/32 (CAN_S), 31/34 (CAN_L), and 30/33 (GND) are interconnected internally for convenient daisy chaining.

Both ends need to be connected to a 120 Ω terminal resistor, and the shielding layer is only grounded at one point.

2. Modbus RTU（H2）

RS-485 two-wire system, terminals 29/33 (A+), 31/35 (B -), 30/33 (GND). Internal interconnection also provides dual terminals for easy branching.

When the distance is long or the number of nodes is greater than 32, the terminal resistance value needs to be calculated based on the internal 22k Ω up/down resistance and external bias, as detailed on page 63 of the manual.

3. Profibus DP（H3）

The wiring corresponds to 9-pin D-sub pins: 3 (B+), 5 (GND), 8 (A -). Shielded twisted pair cables are also used, with a single end grounded.

4. Engine specific communication (H4/H5/H6)

H4：Caterpillar CCM（RS‑232）

H5: MTU MDEC or J1939 (CAN), terminals 128/131 (CAN_S) and 130/133 (CAN_L) are interconnected internally, requiring a 120 Ω terminal.

H6：Cummins ECM（Modbus RTU）， Terminals 127/131 (A+) and 129/133 (B -) are interconnected internally.

Engineering Tip: Regardless of the type of bus, the shielding layer must be grounded only at one point (usually the main station side) and wrapped with insulating tape at the other end to prevent the formation of a ground loop. Use Belden 3105A or equivalent cable (22AWG, shielding coverage ≥ 95%).

Circuit breaker control and synchronization circuit

For GPC/PU, the synchronous closing output is relay 4 (terminals 14-16), while the speed/voltage regulating relay (terminals 65-72) can accept acceleration/deceleration/addition/subtraction pulses from the automatic controller. The feedback of the "closing" and "opening" status of the circuit breaker is connected through binary inputs (such as terminals 54 and 55) to ensure that the software can correctly determine the position of the circuit breaker.

Special attention should be paid to the synchronous closing pulse width and closing advance angle. These parameters are set in the software (menu 2000 series), and should be verified on site through an oscilloscope or synchronous inspection device to ensure that the phase angle difference, slip, and voltage difference are within the allowable range when closing.

Debugging and Power on Inspection Checklist

Insulation test: Before powering on, use a 500V megohmmeter to check the insulation of the AC circuit to ground and between each circuit, which should be greater than 20M Ω.

Power check: Confirm that the power polarity is correct and the voltage is within the rated range.

CT open circuit prevention: When the controller is not connected, the CT secondary side must be short circuited before it can be opened.

Communication test: Use PC terminal software (such as DEIF's Utility Software) to read device information and verify Modbus/DNP communication through RS-232 (J3 option) or USB connection.

Analog calibration: Apply standard voltage and current signals, compare the displayed value on the screen with the actual value, and the error should be less than 1% (negative sequence 2%).

Protection function test: Simulate overvoltage, undervoltage, overclocking, underfrequency, overcurrent, and reverse power separately to confirm that the relay action and alarm output are correct.

Common Problems and Maintenance Suggestions

Problem 1: Frequent controller reset - mostly due to relay inductive loads without suppression circuits, adding RC or varistors is sufficient.

Problem 2: Synchronization closing failure - Check if the voltage and pulse width of the circuit breaker closing coil match, and also confirm if the synchronization check relay (if any) is locked.

Problem 3: Unstable load distribution - Check the shielding grounding and terminal matching of the distribution line to ensure that the power/frequency droop characteristics of each unit are consistent.

Problem 4: Engine cannot start - Check the output of the start relay (terminal 120) and start preparation (124), and confirm that the fuel/start solenoid valve power supply is normal.

Firmware upgrade: Perform via option J3 (serial port) or Ethernet (if configured), backup all parameters before upgrading.